new example, bug fixes

@@ -7,7 +7,6 @@
 *.fls
 *.nav
 *.vrb
-*.out
 *.snm
 *.synctex.gz
 *.toc

+ * add `VBox` and `HBox` to layout data blocks without the need to play
+   with Heaps (fix `examples/qs-main.py` accordingly)

@@ -216,7 +216,7 @@ class Aggregate (CAniTikZ) :
     def __setitem__ (self, key, val) :
         self._d[key].set(val)
     def __len__ (self) :
-        return len(self.d)
+        return len(self._d)
     def stop (self) :
         for v in self._d.values() :
             v.stop()

@@ -170,9 +170,10 @@ class FunctionReturn (Exception) :
         self.RET = RET
 
 class RETURN (_CODE) :
-    _fields = ["value"]
+    _options = ["value"]
     def __call__ (self) :
-        self.value()
+        if self.value is not None :
+            self.value()
         self._at.add(self.IP)
         self.IP += 1
         raise FunctionReturn(self.RET)

-all: heap.pdf qs-partition.pdf
+all: heap.pdf qs-partition.pdf qs-main.pdf
 
 %.pdf: %.py tpl.tex
 	ln -sf ../codanim .
 	rm -f out.*
 	python $<
-	latexmk -pdf tpl
+	pdflatex tpl
+	pdflatex tpl
 	cp tpl.pdf $@
-	latexmk -C tpl
 
 clean:
-	rm -f $$(grep '^*' ../.gitignore)
+	rm -f out.* $$(grep '^*' ../.gitignore)

+from codanim.data import Array, Heap
+from codanim.flow import FUNC, BLOCK, ENV, WS, XDECL, DECL, PY, EXPR, STMT, WHILE, IF
+
+##
+## quicksort partitioning
+##
+
+array = Array([3, 13, 5, 0, 7, 11, 4, 9, 14, 2, 10, 1, 12, 8, 6],
+              index=["a", "b", "p"])
+first = Array(15,
+              aggregate={"grow": "north",
+                         "ticks": "west",
+                         "index": None})
+last = Array(15,
+             index=["top"],
+             aggregate={"grow": "north",
+                        "ticks": None,
+                        "index": "east"})
+
+def part (tab, first, last) :
+    t = [tab[i] for i in range(first, last+1)]
+    a, b, pivot = -1, len(t), t[(len(t)-1)//2]
+    while True :
+        while True :
+            a += 1
+            if t[a] >= pivot :
+                break
+        while True :
+            b -= 1
+            if t[b] <= pivot :
+                break
+        if a >= b :
+            for i, v in enumerate(t) :
+                tab[i+first] = v
+            return b
+        t[a], t[b] = t[b], t[a]
+
+sort = FUNC(BLOCK(ENV("t", array),
+                  ENV("part", part),
+                  ENV("top", None),
+                  ENV("_first", first),
+                  ENV("_last", last),
+                  WS("\n  "),
+                  XDECL("p", "a", "b",
+                        src="uint p, a, b;"),
+                  WS("\n  "),
+                  DECL("first", EXPR("_first", src="stackNew(t.len)"),
+                       src="Stack {name} = {init};"),
+                  PY("top = 0"),
+                  WS("\n  "),
+                  DECL("last", EXPR("_last", src="stackNew(t.len)"),
+                       src="Stack {name} = {init};"),
+                  WS("\n  "),
+                  STMT("first[top] = 0",
+                       src="stackPush(&first, 0);"),
+                  WS("\n  "),
+                  STMT("last[top] = (len(t)-1); top += 1",
+                       src="stackPush(&last, t.len-1);"),
+                  WS("\n  "),
+                  WHILE(EXPR("top > 0", src="!stackEmpty(first)"),
+                        BLOCK(WS("    "),
+                              STMT("a, first[top-1] = first[top-1], None",
+                                   src="a = stackPop(&first);"),
+                              WS("\n    "),
+                              STMT("b, last[top-1] = last[top-1], None; top -= 1",
+                                   src="b = stackPop(&last);"),
+                              WS("\n    "),
+                              IF(EXPR("a < b"),
+                                 BLOCK(WS("      "),
+                                       STMT("p = a + part(t, a, b)",
+                                            src="p = a + partition(slice(t, a, b));"),
+                                       WS("\n      "),
+                                       STMT("first[top] = a",
+                                            src="stackPush(&first, a);"),
+                                       WS("\n      "),
+                                       STMT("last[top] = p; top += 1",
+                                            src="stackPush(&last, p);"),
+                                       WS("\n      "),
+                                       STMT("first[top] = p+1",
+                                            src="stackPush(&first, p+1);"),
+                                       WS("\n      "),
+                                       STMT("last[top] = b; top += 1",
+                                            src="stackPush(&last, b);"),
+                                       WS("\n")),
+                                 src="if ({cond}) {{\n{then}    }}"),
+                              WS("\n")),
+                        src="while ({cond}) {{\n{body}  }}\n")),
+            src="void sort (Tab t) {{{body}}}")
+
+# let's play with Heap to layout the various data blocks
+# /!\ we must do this before simulating the code
+ha = Heap()
+ha.new(array)
+hs = Heap(heap={"grow": "right",
+                "distance": "0pt"})
+hs.new(first)
+hs.new(last)
+h = Heap(heap={"grow": "right",
+               "distance": "5mm"})
+h.new(ha)
+h.new(hs)
+
+# run code and save its animation
+sort.IP += 1
+sort()
+with open("out.code", "w") as out :
+    out.write(sort.tex())
+
+# save data animation
+with open("out.tikz", "w") as out :
+    out.write(h.tex(tikzpicture={"scale": .55}))

@@ -12,6 +12,9 @@
 \usetikzlibrary{arrows.meta}
 \usetikzlibrary{positioning}
 
+\setbeamersize{text margin left=5mm,text margin right=5mm}
+\setlength{\headsep}{-5mm}
+
 \def\hl #1{{\setbox0=\hbox{#1}%
     \adjustbox{set vsize={\ht0}{\dp0}}{\hbox to \wd0{\hss\colorbox{yellow}{#1}\hss}}}}
 
@@ -26,9 +29,14 @@
 
 \begin{document}
 
-\begin{frame}[fragile]
-  \IfFileExists{out.code}{\VerbatimInput[commandchars=\\\{\}]{out.code}}{}
-  \IfFileExists{out.tikz}{\input{out.tikz}}{}
+\begin{frame}[t,fragile]
+  \vbox to 0pt{%
+    \IfFileExists{out.code}{\VerbatimInput[commandchars=\\\{\}]{out.code}}{}
+    \vss
+  }
+  \vbox to \textheight{%
+    \vss\IfFileExists{out.tikz}{\input{out.tikz}}{}%
+  }
 \end{frame}
 
 \end{document}